Electric gong



E. J. DEARY ELECTRIC GONG June 12, 1934.

2 Sheets-Sheet 1 Filed Dec. 22, 1930 lNVENTOR June 12, 1934. E J DEARY 1,962,926

ELECTRIC GONG o Filed Dec. 22, 1950 2 Sheets-Sheet 2 I r as ATORNFV Patented June 12, 1934 UNITED STATES PATENTi OFFICE ELECTRIC GONG Edward J. Deary, Brooklyn, N. Y., Alarm Company,

Automatic Fire assignor to New York,

1 Claim.

The present invention relates particularly though not exclusively to single stroke gongs.

Special objects of the invention are to improve the construction of gongs in the matters of simplicity, durability, ease of assemblage and adjustment, cost of production, to insure reliability and certainty of operation, enable proper testing and checking of the operation, to provide for operation of the device either as a single stroke or as a vibrating bell and in general, to provide a gong construction for fire alarm systems or the like, which will have many practical advantages over devices now in use.

The foregoing and other desirable objects are attained by the novel features of construction,

combination and arrangement of parts as hereinafter disclosed.

The drawings accompanying and forming part of this specification illustrate the present commercial embodiment of the invention, but it should be appreciated that the structure may be modified as regards this disclosure without departure from the true spirit and broad scope of the invention.

Figs. 1 and 2 are front and side elevations respectively of the gong, but with the cap nut which holds the gong top in place removed in Fig. 1 to disclose the mounting of the gong top on the positioning pins carried by the nut which secures the gong post in place; Fig. 3 is an enlarged view as taken on substantially the plane of line 3-3 of Fig. 4, as with the cover of the box removed and with a portion of the gong top appearing in sectime above the plunger; Fig. 4 is an elevation showing the opposite side of the box from that shown in Fig. 2 and with the gong top illustrated in section; Fig. 5 is a central vertical sectional View as on substantially the plane of line 5-5 of Fig. 3; Fig. 6 is a cross-sectional view as on substantially the plane of line 6-6 of Fig. 3; Fig. 7 is a diagrammatic view illustrating modification of the gong from single stroke to vibrating bell operation.

In the gong illustrated, the parts are all housed within or carried by a box '7 having a hollow cover 8 removably secured by the screws 9.

A bi-polar electro-magnet 10 is shown carried by a base plate 11 secured by screws 12 to the back wall of the box and at the foot of this base plate a bracket 13 is shown adjustably secured by screws 14 passing through slots 15 in the bracket into the back plate. This adjustably secured bracket serves as a mounting for the armature 16, which is shown as pivoted on said bracket at 1'7.

(Cl. 177--7) i The armature actuates a hammer plunger 19 guided in a tube 20 and adapted to be engaged at its lower end by the forwardly projected extension 21 of the armature.

The down-stroke of the armature is shown as regulatable by a stop screw 22 passed up through the bottom wall of the box into position to form a rest for the armature extension and adapted to be held in adjusted relation by a lock nut 23, Figs. 4 and 5. This stop screw may be utilized also to adjust the falling movement or back stroke of the hammer plunger, but the latter preferably may be independently governed as by a cross pin 24 in the upper end portion of the same designed to cooperate with a stop shoulder on top of the box. This arrangement is desirable as providing a slight lost motion between the armature and plunger, enabling a certain degree of acceleration of the armature before it picks up the plunger.

The guide tube 20 is shown as having bearing rings 25 set in the upper and lower ends of the same to provide widely spaced loose frictionless bearings for the plunger, said rings being rounded or bevelled toward the plunger to reduce the 50 areas of contact with the plunger. These reduced area bearings may be secured with a pressfit in the opposite ends of the tube and their efiect is to guide the plunger freely at all times without any binding action and without requiring 5 any lubrication or other attention. The guide tube is shown as secured in position extending up through the top wall of the box by lock washers 26 and nuts 27 engaged over the externally threaded upper end portion 28 of the tube above and below the box wall.

To exclude dust and moisture from the box, a washer 29 of felt or other suitable'material is shown engaged on the protruding upper end portion of the plunger, arranged to cooperate with the upper end of the guide tube and backed up by a washer 30 beneath the cross pin 24. In the position of rest, this dust washer substantially seals the plunger opening in the top of the guide tube, but does not interfere with the operation of the plunger, as it is simply a floating member on the plunger beneath the washer 30 which similarly may be a loose member on the plunger caught beneath the stop pin 24.

To prevent removal of the plunger when the gong top is taken off and hence to insure against the gong top being replaced without the plunger in position, a cotter pin 31 is shown passed through the lower-portion of the plunger beneath and separated from the lower end of the guide tube a sufficient distance not to interfere with the free stroke of the plunger.

The gong top 32 is adjustably mounted in the present illustration by having the bolt 33 which supports it adjustably secured on the box cover. Thus as shown in Figs. 5 and 6, this bolt passes through a slot 34 in the cover and is arranged withitshead 35 inside the box cover slidably confined between two spaced parallel ribs 36 at opposite sides of and parallel to the slot 34. A plate 37 covers the slot and is of a width to slide in the way between the ribs 36, beneath the head of the bolt. A washer 38 on the bolt covers the slot at the outside and a nut 39 on the bolt over this washer serves for securing the bolt in its adjusted relation.

It will be observed that upon loosening nut 39, the bolt 33 which serves as a post for supporting the gong top can be adjusted vertically and the gong be thereby set with its upper edge in the desired spaced relation to the end of the plunger. The bolt is held against turning by the sliding engagement of its head between the flanges or ribs on the inner face of the cover. The plate 37 serves as a runner for the bolt head, enabling the same to slide freely between the guide ribs and this plate at the inside together with the washer on the outside, enable the bolt to be secured in accurate outstanding relation regardless of its vertical adjustment. The gong top is held in non-rotatable relation on the sup porting post by the pins 40 on the outer face of the bolt securing nut 39 entered in corresponding recesses 41in thegong top. These recesses are shown as formed as extensions or continuations of the central opening 42, provided to receive the bolt and as shown in Fig. 1, the pins 40 and recesses 41 are all located to one side of a diametrical line, so that the gong top will only go over the bolt to its seated position on the nut .in this one relation of the parts.

A cap nut 43 engaged over the outer end of the bolt serves for removably securing the gong top in position and for clamping the same in rigid engagement with the circular seat 44 provided for it on the outer face of the nut 39.

In the present disclosure, an auxiliary circuit or the gong circuit may be controlled, by operation of the gong, through the provision of. cooperating spring contacts 45, 46, Figs. 3, 5; 6 and 7, supported by an insulating block 4'7 in posi tion for engagement by a circuit closing insulating button 48 on the armature lever 21. The insulating base which carries these contacts is shown as mounted on a bracket 49 secured to the side wall of the box and the contacts are shown in Fig. 3 as connected by wiring 50, 51, with suitable insulated terminals 52, 53 on the outside of the box. It will be seen that upon each stroke of the gong, the lower spring contact will be lifted up into engagement with the upper spring contact and hence that this mechanism may be employed for controlling a supervisory or indicating, or other auxiliary circuit connected with the terminals 52, 53. The auxiliary circuit contacts are relatively light and flexible, so as not to retard or otherwise impair the action of the IIg.

To enable ready checking of the gong and the circuit in which it is connected, grounding and circuit interrupting switches are mounted on the side of the box opposite the side on which the auxiliary switch terminals are placed. As shown in Fig. 4, the grounding switch comprises a switch lever 54 pivoted on a grounding terminal 55 and adapted to be swung from a mid-position on an insulating block retainer 56 over into engagement with either one of the contact clips'57, 53, the first being connected with one of the line terminals 59 and the other being connected 'by a back connection 60 with the other line terminal 61.

The upper line terminal 59 is shown in Fig. 3'

as directlyconnected at 62 with one side of the electromagnet but, as shown in Fig. 4, the lower line terminal61 is connected in the magnet circuit through a circuit interrupting switch consisting of a switch lever 63 engaging a contact clip 64 at the end of bar 65, which connects with the-clip-58, said lever being pivoted on a post 66, connected at 6'7, Fig. 3, to the other side of the magnet circuit. This switch lever is acted on by a spring 68 normally holding the lever in the circuit closed relation. This switch lever however may be shifted by the handle 69 against a stop pin '70, Fig. 4, to open the magnet circuit and when released, instantly snaps back into the circuit closed relation. The U-shaped spring contact clips 57, 58, 64, Figs. 3 and 4, firmly engage over the ends of the switch levers 54 and 63 to insure good contact and to. serve as guards for the free ends of the switch levers, preventing them from being lifted out of contact making relation.

The testing switches may be made up on a single insulating base 71 attachable as a unit over the side wall of the box as by nuts applied to the switch lever pivot studs 66 and '72, at the inside of the box as indicated in Fig. 3.

All parts of the mechanism are of simple, sturdy design and the structure as a whole is reliable, practical and efiicient.

The forwardly projecting extension on the pivoted armature operates on the plunger as a lever and because of the acceleration permitted by its spacing from the lower end of the plunger gives the plunger a quick forceful hammerlike blow, which will overcome any sticking tendency of the plunger. Also by this construction, the stroke of the plunger is long enough to provide the proper spacing between the plunger and gong top.- The adjustability of the gong top enables this spacing and the relative position of the gong top on the box to be varied as conditions may require. The plunger is guided substantially without friction and being practically sealed within the guide tube, can be relied upon to operate smoothly and easily indefinitely regardless of dust or atmospheric conditions. The guide tube itself being held in the top wall of the case by nuts above and below said wall is capable of a certain amount of vertical adjustment and may be readily removed and replaced when necessary. In addition to sealing the guide tube, the felt-like washer cushions the back stroke of the plunger, thus serving in effect as a partial silencer for the striker mechanism.

To insure quick return of the plunger, a light coil spring '75 is shown surrounding the plunger and interposed between the cross pin 31 and the lower end of the guide tube, Figs. 3 and5.

The plunger returning spring 75 is desirable when the gong is used for vibrating bell operation, as it may be by connecting the auxiliary switch contacts in series relation with the magnet, as indicated in Fig. 7. In this particular case, the contacts are biased to a circuit closed relation and the upper contact 45 is provided with an extension 45a positioned to be engaged by the button on the armature lever to interrupt the magnet circuit. With this construction and arrangement, it will be seen that the plunger will be reciprocated or vibrated whenever the signal circuit is closed. The invention thus provides in effect a universal gong as the change from single stroke to multiple stroke may be readily made by simply substituting the Fig. 7 form of contact interrupter for the Fig. 3 form of auxiliary circuit closer and connecting the auxiliary circuit in series relation with the gong magnet.

By the substitution of gong mounting washers 38 or nuts 39 of different thickness, Figs. 4 and 5, different sizes and shapes of gong tops may be set so as to be properly engaged at the edge by the striking plunger.

The test switches are conveniently located on the side of the gong box, thus forming actually a part of the gong. Grounding switch 54 may be used to complete the gong circuit through the grounded side of the battery, if the other side of the line, carrying the battery power, should be broken, said switch then serving to keep the gong in operative condition. Other uses of this and the circuit interrupting switch 63 will be apparent to those skilled in this art.

Because of the possibilities of modification, within the scope of this invention, the terms employed herein have been used in a descriptive rather than in a limiting sense, except possibly for such limitation as may be imposed by the state of the prior art.

What is claimed is:

A gong comprising a supporting structure, an electro-magnet mounted thereon and having a pivoted substantially vertically operating armature, a substantially vertically disposed guide tube, a plunger loosely guided in said guide tube and positioned thereby to be operated by said armature, cooperating stops on said plunger and guide tube limiting downward movement of the plunger in the guide tube, a gong top mounted on the supporting structure for striking by the plunger and means for mounting the plunger guide tube in vertically adjustable relation on the supporting structure in position for supporting the plunger with the lower end of the same spaced above the substantially vertically operating armature and the upper end disposed to strike the gong top and whereby the extent of lost motion between the armature and plunger and the spacing of the plunger with respect to the gong top may be fixed by securing said guide tube in vertically positioned relation on the supporting structure.

EDWARD J. DEARY. 

